<!DOCTYPE html>
<html lang="en">
	<head>
		<title>three.js - kinect</title>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
		<link type="text/css" rel="stylesheet" href="main.css">
	</head>
	<body>

		<video id="video" loop muted crossOrigin="anonymous" playsinline style="display:none">
			<source src="textures/kinect.webm">
			<source src="textures/kinect.mp4">
		</video>

		<script id="vs" type="x-shader/x-vertex">

			uniform sampler2D map;

			uniform float width;
			uniform float height;
			uniform float nearClipping, farClipping;

			uniform float pointSize;
			uniform float zOffset;

			varying vec2 vUv;

			const float XtoZ = 1.11146; // tan( 1.0144686 / 2.0 ) * 2.0;
			const float YtoZ = 0.83359; // tan( 0.7898090 / 2.0 ) * 2.0;

			void main() {

				vUv = vec2( position.x / width, position.y / height );

				vec4 color = texture2D( map, vUv );
				float depth = ( color.r + color.g + color.b ) / 3.0;

				// Projection code by @kcmic

				float z = ( 1.0 - depth ) * (farClipping - nearClipping) + nearClipping;

				vec4 pos = vec4(
					( position.x / width - 0.5 ) * z * XtoZ,
					( position.y / height - 0.5 ) * z * YtoZ,
					- z + zOffset,
					1.0);

				gl_PointSize = pointSize;
				gl_Position = projectionMatrix * modelViewMatrix * pos;

			}

		</script>

		<script id="fs" type="x-shader/x-fragment">

			uniform sampler2D map;

			varying vec2 vUv;

			void main() {

				vec4 color = texture2D( map, vUv );
				gl_FragColor = vec4( color.r, color.g, color.b, 0.2 );

			}

		</script>

		<script type="module">

			import * as THREE from '../build/three.module.js';

			import { GUI } from './jsm/libs/dat.gui.module.js';

			let scene, camera, renderer;
			let geometry, mesh, material;
			let mouse, center;

			init();
			animate();

			function init() {

				const container = document.createElement( 'div' );
				document.body.appendChild( container );

				const info = document.createElement( 'div' );
				info.id = 'info';
				info.innerHTML = '<a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> - kinect';
				document.body.appendChild( info );

				camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 1, 10000 );
				camera.position.set( 0, 0, 500 );

				scene = new THREE.Scene();
				center = new THREE.Vector3();
				center.z = - 1000;

				const video = document.getElementById( 'video' );

				const texture = new THREE.VideoTexture( video );
				texture.minFilter = THREE.NearestFilter;

				const width = 640, height = 480;
				const nearClipping = 850, farClipping = 4000;

				geometry = new THREE.BufferGeometry();

				const vertices = new Float32Array( width * height * 3 );

				for ( let i = 0, j = 0, l = vertices.length; i < l; i += 3, j ++ ) {

					vertices[ i ] = j % width;
					vertices[ i + 1 ] = Math.floor( j / width );

				}

				geometry.setAttribute( 'position', new THREE.BufferAttribute( vertices, 3 ) );

				material = new THREE.ShaderMaterial( {

					uniforms: {

						"map": { value: texture },
						"width": { value: width },
						"height": { value: height },
						"nearClipping": { value: nearClipping },
						"farClipping": { value: farClipping },

						"pointSize": { value: 2 },
						"zOffset": { value: 1000 }

					},
					vertexShader: document.getElementById( 'vs' ).textContent,
					fragmentShader: document.getElementById( 'fs' ).textContent,
					blending: THREE.AdditiveBlending,
					depthTest: false, depthWrite: false,
					transparent: true

				} );

				mesh = new THREE.Points( geometry, material );
				scene.add( mesh );

				const gui = new GUI();
				gui.add( material.uniforms.nearClipping, 'value', 1, 10000, 1.0 ).name( 'nearClipping' );
				gui.add( material.uniforms.farClipping, 'value', 1, 10000, 1.0 ).name( 'farClipping' );
				gui.add( material.uniforms.pointSize, 'value', 1, 10, 1.0 ).name( 'pointSize' );
				gui.add( material.uniforms.zOffset, 'value', 0, 4000, 1.0 ).name( 'zOffset' );

				video.play();

				//

				renderer = new THREE.WebGLRenderer();
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( window.innerWidth, window.innerHeight );
				container.appendChild( renderer.domElement );

				mouse = new THREE.Vector3( 0, 0, 1 );

				document.addEventListener( 'mousemove', onDocumentMouseMove );

				//

				window.addEventListener( 'resize', onWindowResize );

			}

			function onWindowResize() {

				camera.aspect = window.innerWidth / window.innerHeight;
				camera.updateProjectionMatrix();

				renderer.setSize( window.innerWidth, window.innerHeight );

			}

			function onDocumentMouseMove( event ) {

				mouse.x = ( event.clientX - window.innerWidth / 2 ) * 8;
				mouse.y = ( event.clientY - window.innerHeight / 2 ) * 8;

			}

			function animate() {

				requestAnimationFrame( animate );

				render();

			}

			function render() {

				camera.position.x += ( mouse.x - camera.position.x ) * 0.05;
				camera.position.y += ( - mouse.y - camera.position.y ) * 0.05;
				camera.lookAt( center );

				renderer.render( scene, camera );

			}

		</script>
	</body>
</html>
